Researchers and bioethicists have developed guidelines to protect human subjects in clinical experiments involving genetic technologies. However, these rules were developed for investigations of therapeutic interventions and do not address the risks involved in the potential use of genetic technologies for enhancement purposes. Society has reached a clear consensus against attempting germ-line genetic interventions in humans, but genetic knowledge could still be used for enhancement purposes in other ways, such as the somatic use of biosynthetic growth hormone to increase stature, or studies to identify genetic mutations associated with non-disease traits. In the absence of guidelines that explicitly address the special issues of enhancement research, subjects could be exposed to risks that would be acceptable in the case of therapeutic research but unacceptable in the case of enhancement research. Moreover, the absence of explicit enhancement research policy is likely to drive this type of research into the realm of "underground" illicit or off-label use and self-experimentation, which could cause serious harm to research subjects and to society. To address this policy gap, this project will identify ethically relevant differences between therapeutic and enhancement genetic research and analyze these differences in terms of the ethical principles that govern human subjects research, in order to determine whether current rules and regulations adequately restrict enhancement research, and, if not, propose changes to existing rules and regulations so that society can respond effectively to possible future attempts to conduct genetic enhancement research using human subjects.